Holddown fastening clip with grating and sub-support structures

ABSTRACT

A U-shaped fastener clip for fastening down barred gratings such as the parallel barred gratings frequently used for entranceways and elevator floors. The fastener clip is located below the upper level of the bars between two supporting joists of the floor gratings to which the bars are integrally connected. Slotted extensions on each end of the clip fit between the bars and engage the joists. The bottom part of the clip includes fastening means which engage a supporting sub-structure. In position, the clip lies entirely below the surface of the grating thus providing a blind or substantially concealed fastening.

HOLDDOWN FASTENING CLIP WITH GRATING AND SUB-SUPPORT STRUCTURES BACKGROUND OF THE INVENTION space between the bars is utilized to allow dirt and other materials to pass between the bars and into an open space below. In some entranceways air is blown from above through the grating to form an air curtain separating the cooled or interior of the building from the outdoors. Common methods for retaining the floor gratings in place require that fittings be attached to the floor grating or a portion of the floor grating bars be cut away and adapted for proper engagement with a flush screw or other retaining device. More specifically, either a hole is cut through the grating bars and a fitting welded to the supporting joists below the grating bars or a section of the grating bars is cut away and a flush flat plate welded in place having a bolt hole therein. These techniques result in an unsightly disturbance to the appearance of the floor as well as significant added costs of fabrication. In addition, the barred gratings have found further use as covers for heating and ventilating equipment. For example, after fabrication, the barred gratings are bent to shape to cover electric or hot water heating conduits. Esthetic appeal is important for such architectural use, therefore, unsightly disturbances to the appearance of the grating is of significant importance.

SUMMARY OF THE INVENTION The invention comprises a generally U-shaped fastener clip having slotted outward extensions on each upper edge of the U. The extensions hook over the joists and fit between the bars of the grating. The bottom of the U-shaped fastener includes means for tightening the fastener clip and floor grating down into place.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of a prior art floor grating fasten- 8;

FIG. 2 is a side elevation of a typical prior art floor grating fastening;

FIG. 3 is a perspective view of applicants new fastener clip as installed;

FIG. 4 is a side elevation of the new fastener clip as installed; and,

FIG. 5 is a perspective view of a cover grating showing the fastener clips as installed in cutaway;

FIG. 6 is an alternate form of the fastener clip including a crowned and ribbed body.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 2 a floor grating 8 is shown installed in an elevator floor. The floor grating comprises grating bars 10 welded to grating joists 12 which in turn rest upon rubber flooring 14. The supporting substructure includes a floor plate 16 fastened to a frame 18 surrounding the floor grating 8. A typical prior art fastening is shown and comprises a flat head bolt 20 screw ed into a threaded hole 22 in the floor plate 16. A circular plate 24 is welded into a hole 26 cut into the grating bars 10 and includes a countersunk hole 28 for the bolt 20. Thus the prior art requires a cutting, fitting and welding operation at each location where the floor grating is to be fastened into place. The plate 24 and bolt 20 although flush with the grating bars 10 disturb the continuity and appearance of the floor grating which is important from an architectural aesthetic view. In addition, axial alignment problems between the plate 24 and floor screw hole 22 are encountered.

Applicants new fastener clip is shown in FIGS. 3 and 4 as installed in the same elevator floor as above. The fastener clip generally denoted by 30 includes a bottom portion 32 and side portions 34 and 36. At the upper edge of each side portion 34 and 36 are outward slotted extensions 38 which fit over and engage upper edges of two of the floor joists 12. The extensions 38 between slots fit between the bars 10 and as installed are preferably below the top surface of the bars 10. An Allen Head screw 40 engages the bottom of the clip 32 through an elongated slot 42 and engages the elevator floor plate 16 in a threaded hole 44. The Allen Head screw is selected with a wrench size sufficiently small enough to allow the Allen Head wrench 46 as shown in FIG. 4 to fit between the grating bars 10.

The fastener clip is made of sheet metal or other material sufficiently flexible to allow the sides 34 and 36 to be squeezed slightly and thereby permit the clip to be inserted between the joists 12 prior to setting the floor grating 8 in place. The slot provides for lateral adjustment between the clip and floor grating. Alternate means may be employed for retaining the bottom 32 of the clip to the elevator support floor and the clip fastener is not specifically limited to the means shown. It is apparent that no cutting, fitting or welding of the floor grating is required for the use of applicants clip. The appearance of the floor grating is not marred by any discontinuity at the fastening locations.

FIG. 5 shows an alternate installation wherein the floor grating has been shaped to cover heating and ventilating equipment not shown. The fastener clips are inserted and installed in the same manner as for the floor above. The Allen Head screws 40 engage threaded holes 48 in the supporting substructure 50. Here again, an Allen Head wrench 46 can be inserted between the bars 10 to tighten down the screw 40.

In an alternate form, in FIG. 6, the bottom portion 132 is crowned upwardly as shown and includes ribs 133 extending substantially from side 134 to side 136. The ribs and crown allow use of a lighter gage of metal thereby improving the spring action of the clip when the sides are squeezed to allow insertion between the joists 12 but nevertheless retaining the necessary resilience and strength to provide sufficient hold down force. The spring action allows for easier release of the clip from above with the use of a pointed tool to snap the extensions 138 inward and downward.

I claim:

1. An open barred grating structure comprising in combination cross support members, open barred grating rigidly mounted thereon, a sub-support structure, generally U-shaped blind fastener means comprising a bottom, two sides, and side edges terminating in multiple slotted lateral extensions adapted to engage said support members between said grating bars, and attachment means joining said bottom to said subsupport structure.

2. The grating structure of claim 1 wherein said side edge extensions are oppositely directed from substantially parallel sides.

3. The grating structure of claim 1 wherein said bottom includes an elongated slot, and said attachment means include an Allen Head screw extending through said elongated slot, engaging said sub-support structure and accessible by an Allen Head wrench passing between adjacent grating bars.

4. The grating structure of claim 1 wherein said bottom is crowned to provide added lateral spring action to the sides.

5. The grating structure of claim 1 wherein said bottom includes ribs extending perpendicular to said sides to provide added rigidity to said bottom.

6. A floor structure comprising in combination an and said sub-support structure. 

1. An open barred grating structure comprising in combination cross support members, open barred grating rigidly mounted thereon, a sub-support structure, generally U-shaped blind fastener means comprising a bottom, two sides, and side edges terminating in multiple slotted lateral extensions adapted to engage said support members between said grating bars, and attachment means joining said bottom to said sub-support structure.
 2. The grating structure of claim 1 wherein said side edge extensions are oppositely directed from substantially parallel sides.
 3. The grating structure of claim 1 wherein said bottom includes an elongated slot, and said attachment means include an Allen Head screw extending through said elongated slot, engaging said sub-support structure and accessible by an Allen Head wrench passing between adjacent grating bars.
 4. The grating structure of claim 1 wherein said bottom is crowned to provide added lateral spring action to the sides.
 5. The grating structure of claim 1 wherein said bottom includes ribs extending perpendicular to said sides to provide added rigidity to said bottom.
 6. A floor structure comprising in combination an open barred grating, cross support joists rigidly fastened to said grating, a sub-support structure, a plurality of generally U-shaped fastener means providing spaced attachment points each comprising a bottom, two sides, and side edges terminating in multiple slotted lateral extensions adapted to engage said support joists between said grating bars, and a plurality of attachment means engaging said bottoms and said sub-support structure.
 7. The floor structure of claim 5 wherein said bottoms include an elongated slot and said attachment means include threaded fastener means accessible through adjacent grating bars and engaging said bottom and said sub-support structure. 